Mix sugar, milk, margarine, salt and corn syrup in saucepan using a wooden spoon. Bring to boil over medium heat and cook 5 minutes, stirring constantly.
Remove from heat; add chocolate chips and vanilla extract. Mix well and add 3/4 cup of the coconut and spoon into buttered 11 x 7-inch pan. Fudge will be too thick to pour. Smooth in pan with wooden spoon. Press remaining coconut on top of fudge and mark into 1 1/2-inch squares. When cool, cut squares through. Makes about 2 pounds.